if you mean controlling brightness using a PWM signal, the Explorer outputs are not suitable. Your best bet is actually to tap straight onto the GPIO header, on bcm18.
… if I misunderstood the question, please post additional context as it is not really clear what your bill of material is and what you are trying to achieve.
hey, you are right, the API does support PWM through the Explorer outputs, I forgot about that.
The key thing to remember/understand is that the Explorer uses a Darlington array to drive its outputs, and as such can only sink to ground, not supply power. That means that your logic needs inverting.